Open DevTools on LinkedIn and you’ll see hundreds of failed fetches pile up within seconds. LinkedIn ships a list of roughly 5000 browser extension IDs and probes every single one to see which ones you have installed. The trick is old but effective: request an asset you know ships inside the extension, and a successful load means it’s there.

const o = [{id:"d", file:"icon/16.png"},
           {id:"aabfjmnamlihmlicgeoogldnfaaklfon", file:"Assets/48.png"},
           /* ...4932 more */
           ]

Most of the list is what you’d expect: lead gen and CRM sidebars, scrapers, email and phone finders, recruiting and ATS helpers, resume writers, AI cold-email tools. That one ID above is “Writecream”, which offers to read your prospect’s profile and “write the coolest cold emails for you”. 440 of the names are in non-Latin script, so the harvesting economy is global.

There’s a second route too. A function that walks every text node and attribute looking for the literal string chrome-extension://, extracts whatever ID it finds, and reports it. That catches extensions that aren’t on the list yet, which makes it a discovery pipeline for growing the list. Both routes are gated on navigator.userAgent.indexOf("Chrome") > -1, so Firefox and Safari skip the whole thing. Which I guess makes sense if you’re only looking for Chrome plugins, but it does beg the question what this is for.

Reading it as LinkedIn fighting the AI slop flooding their platform is fair. But the list doesn’t look curated so much as bulk-ingested from anything that ever touched the domain. It fingerprints jigsaw puzzle extensions, manga trackers, and a whole (hilarious) counter-culture wing:

• DelinkedIn translates recruiter-speak into what it actually means, but only has 3 users according to the Chrome Plugin store.
• LinkedOFF does parody post rewriting with a whopping 11 users,
• “Ai Slop Replacer”
• “No more Musk”
• “Chess Instead of Posts”
• Then there’s one that auto-solves LinkedIn’s own Tango puzzle, and an “Anti-Human Torture Game”.
• Grammarly and its 36 million users.
• …

You get the idea.

Whatever the intent, the outcome is that your extension set is a decent fingerprint of you, and LinkedIn reads it on every page load. If you want to know who else does this, browsergate.eu tracks it. Although, be aware that browsergate.eu has its own agenda. It’s from an entity called “Fairlinked - Alliance for digital fairness e.V.” a group of commercial LinkedIn users as well as tool and plugin makers that obviously do not like the idea of LinkedIn banning their tools. So for now it seems the only digital fairness they seek is to automate LinkedIn usage.